Multiple contact bank



Jan.1,1929. l*

- l K. BHME MULTIPLE CONTACT BANK Filed Nov. 25, 1922 '3 sheetssheet 1 Fig. 4

FI`G3.

KuTT Bhme Jan. l, 1929. K. BHME'- MULT11=LE CONTACT BANK '5 SheecSheet 2 Filed- Nov. 25. 19,22

Imran DP KW Enhms Jan. 1, 1929. 1,697,222

K. BHME' 2 MULTIPLE coNTAcT BANK.

Filed Nov. 25, 1922, 3 Sheng-sheet 3 IMF- Ku' B-nhma jffi@ Patented Jan. 1, 1929.

UNITED s'r..rl`:'s,

PATENT oFFlca. v`

zum nom, or 3mm-amuseren, enana-ANY, salomon 'ro s a man axmnensamscnarr, or wsmvanwnnx, smxanssran'n, aan.

nomina comac'r am? i apumion 'mea november as, 19:2, seran no. 903,141, and m aemmlynimm-yv s, .ma

The invention relates to a-method of constructing and interconnecting bank contacts, which is specially suitable for forming the multiple cable, and contact banks for tele`v phone switches. The new construction enables the manufacture of Vcable and contacts to be simplified and cheapened. l

For its construction, use'is made of bare conductors located in parallel. According to` the invention these conductors are provided at intervals with insulatino` pieces, which preferablyare made stiff and so shaped that their edges which cross the conductors are located at' an acute angle tothe latter, wblle the two side edges runtparallel'to the conductors. f V f' After. the insulating pieces have been fixed on the conductors, the arts oftheun'coiled cable that have no insu ation are lirst of all so 'kinked that the direction of the conductors at the bends departs from .the direction ofthe uncoiled band. Thereupon the band is folded at the points where there is -no insulation,

projecting end pieces which serve for fixing the cable" to the switch racks. l

cable constructed according to the invention. Figure 1 shows a front view of the cable before it has been kinked or folded. Fi ure 2 2A shows a cable that has been kinked and partly folded, while Figure 3 shows a cable that as been completely kinked and folded for the purpose of formlng the contact bank in combination with the intermediate plates. Figure 4 is a plan view'ofjthe cable shown in three times, of a'section of y e bank showni in Figure 3, with the lower end -raised about from the horizontal. At the. left-hand edge the insulating plates and the stiening plate are provided Aatthe si es of the band with* .Figure 3. Figure 5 is a to view'v enlarged I 1aed pate J is hel in the Same are cut away for a short distance that the conductors can be easilytraced. The bare andI parallelly located conductors L are first of all embedded in plates J, J .1, -J

and J 3 (Figure 1)'loca'ted atadistanoe froml one another, these plates being formed out of a lastic insulating mass, which has been solldified by a process which does not affect the present inventionA and therefore need not be further explained. The insulatingv plates l J, etc., are so arrangedthat their side edgles -Qrun parallelto the conductors L, while t e `o ther two .edges R of each-plate run at an acute angle to these conductors. In the example shown the cable contains three groups of conductors, each group containing 10 conv ductors. In'the example shown, those parts of the cable that are not covered by the msuvlatingpieces are made of different widths, a

.wide space K succeedinga small space K1. `The reason forthis will l explained herein- The insulating'plates J, etc., having been formed on "theconductors, the .conductors L are kinkedin the manner shown in Figure 2 at theparts K, Klthat have no insulation.

Thisisrdone so that in the coiling or foldin operation that ,subsequently takes place b contacts! be formed which lie in planes perpendicular to the plane of the bank;

The flat cable is now coiled in the manner shown in Figs. 2, 3and 5 by .folding the insulating platesY J, etc., against one another.

Thus in succession ever vtwo plates are so.

folded against one anot er that their edges R, between which the spaces K1 in Figures 1 .l and 2 are located, cover one another. The The drawing shows b way of example a two edges R cover one another, intermediate metallic stiiiening pieces P are provided'for the purpose of forming a stiifening. These pieces vpreferabl comprise iron plates, which are connected'with the plates J, etc., by means I of rivets.`

- vThemethodofformn the cable as shown in Figures and 5'fron1 t e form as shown in Figures 1," and 2 will now be described more in detail. Referrn Ato Figure 2 the insuition as shown in Fi es 1 and2.' The p atea J1, J and'J are t en bent u and around to the rightthrough an arco 18,0 degrees so that ma.v

the edges R of the plates J and J1 lie fiat against one another. The Wires that formerly Were in the space K1, in Figure 2, lare formed into loops O on the left side by a rod having first been inserted to form them when the plates were turned. The stiffening piece P is then inserted between the plates J and J1 where they overlap oneanother and isthen fastened to the plates by the rivets N. The cable is now in the position as shown in Figure 2^ with the plates J 2 and J3 extending to the right of the partly formed cable. In the next step the plate J 2, together with the plate J 3 are moved back and around so that J 2 lies back of and under the lower end of plate J1 with the Wires that formerly were in space K forming the loops B on the right as seen in Figures 3 and 5. The last plate J3 is then turned up and around, from the left, on top of the lower end ofplate J1 and is now in a similar position to plate J1. Another stiffening piece P is then inserted and the `parts riveted together. The .whole cable has now assumed the shape of a fiat spiral withthe bank contacts O on the left and the multiple contacts B on the right.

When the cable is coiled by folding the insulating lates J, J1, J2 and J3 against one another t e parts of the conductors L that lie in thespaces K, K1 and which have been kinked in the manner shown in Figure 2 are bent in the manner shown in Figures 2A, 3 and 5. thus forming loops O and B at opposite edges of the flat cable. The loops O lie directly on the edge of the insulating plates and are comparatively short. These loops form the contacts of the bank field, that is to say, the loops se-rve as the fixed contacts over which the wipers of the switches are moved. The loops B, which are remote from the edge of the insulating plates and yare longer than 4the loops O, serveas a multiple to connect corresponding contacts in different groups together and can be used for attaching multiple bank cables where necessary.

The stii'ening plates P are provided with end pieces Z for the purpose of fixing the cable to the switch racks.

A number of stiff' frames are formed by the process of folding the insulating plates J, J1 J2 and J 3 against one another during the coiling of the cable and by at the same time insertlng the stiening plates P. These frames carry the contact loops O. The use of stiffening plates P is not essential, however. If the insulating plates'are sufficiently stiff the end pieces Z can be fixed to them, thu's avoiding thel use of separate stiffening plates. The insulating plates can be made elastic if stiiening plates P are used.

The gap in the insulating material at the point K (Figures land 2) is greater than is required for coiling the cable, as pointed out before. This larger gap in the insulating material renders the loops B very flexible; hence inaccuracies in the manufacture of the racks can be neutralized by pressing frames towards or away from one another when mounting the frames on the switch racks.

vWhat I claim and desire to protect by Letters Patent is l 1. A multiple contact bank comprising a row of insulated plates. a second row ot' similar plates superimposed on said vfirst row, the plates of the second row overlapping those of the first, means securing said plates together in pairs, each pair comprising pla-tes in different rows, a metal plate secured between the insulating plates of each pair, said metal plates having extensions for use in attaching the bank to a frame, and continuous parallel wires extending diagonally through all said plates in series.

2. A multiple contact b-ank comprising pairs of overlapping insulating plates arranged in two rows opposite one another, parallel wires extending through said plates alternately in each row to form a flat spiral, means for securing each pair of said plates together, a metal plate secured to and between each of said pairs of plates, and means on said metal plate :for attaching said contact bank to a frame as a unit.

3. A. multiple contact bank comprising pairs of overlapping insulating plates' arranged in parallel rows and fastened together at the portion where they overlap, parallel wires extending through said plates alternately in each row to form al spiral shaped unit, and a metal plate secured between each of said plates where they overlap, said metal plate having extensions for attaching said unit to a frame.

Signed by me at Berlin, Germany, this 11th day of October, 1922. i KURT BOHME. 

